The field of the invention generally relates to apparatus and method for popping popcorn in a microwave oven, and more particularly relates to a disposable popcorn package and a method of supporting such package during popping.
As is well known in the microwave heating art, popcorn is a relatively non-lossy substance primarily due to its low water content and small size. More particularly, if dry popcorn kernels are placed on a flat plate and exposed to microwave energy in a microwave oven, only a relatively small percentage of the kernels will pop within a reasonable time period because man of the kernels will not absorb microwave energy rapidly enough to reach a popping temperature. Further, if the time period is extended, kernels that have already popped will scorch.
U.S. Pat. Nos. 4,158,760 and 4,586,649, both of which are assigned to the same assignee as the present invention, describe apparatus and method for forming the unpopped kernels into a clump. It was found that clumping greatly increases the popping yield (i.e. percentage of popped kernels) because, among other things, heat losses from kernels are absorbed by adjacent kernels such that the overall temperature of the entire clump is higher than if the kernels were spaced from each other. In particular, a container such as a plastic conical bowl has a lower region of restricted internal volume which forms the kernels into a clump. Then, even after unpopped kernels are disturbed from the clump by other kernels popping, the inclined walls of the cone direct the unpopped kernels by gravity back to the clump.
U.S. Pat. No. 5,045,659, which is assigned to the same assignee, describes a disposable microwave container or package that relies on the above-described principle of clumping to obtain high yield popping. In particular, the container is initially can-shaped and when the kernels pop, a plurality of downwardly converging verticals folds open up or fan out to form a cone-shaped container. One drawback of this arrangement, however, is that the container cannot be manufactured using conventional microwave popcorn bag machines.
One commercially available disposable popcorn package uses a bag of substantially rectangular cross-section that has an inner vapor and grease barrier layer, an intermediate layer with a susceptor or microwave absorber applied thereto, and an outer paper layer on which the instructions and other information are printed. The bag has inwardly pleated side panels and is initially flat with ends folded over to provide a compact package for shipping and storage. In use, the bag is placed in the microwave oven with the ends projecting upwardly, and then microwave energy is applied. The heating of the kernels by absorption o microwave energy is assisted by heat conducted from the microwave susceptor which also heats in response to the microwave energy. In such manner, a relatively large percentage of the kernels reach popping temperature within a reasonable period of time, thereby preventing scorching of already popped kernels. One problem with such package is that the microwave susceptor which, for example may be a conductive film, substantially increases the cost of the package.
Another commercially available microwave popcorn package uses a folded bag similar to the above-described susceptor bag except that rather than using a susceptor layer, the kernels are coated with or embedded in grease, oil, or a similar cooking agent which is lossy. Thus, relatively high yield is attained by a boost in kernel temperature coming from the grease rather than the susceptor film in the package. One problem with such arrangement is that the dietary restrictions or preferences of some consumers prohibit the use of grease or other oils. Also, some consumers may want to apply a particular seasoning of preference rather than the grease or oil supplied by the manufacturer.